Objectives: In Japan, the population is aging and there is a declining birth rate. It is an important occupational health issue to support the balance between illness treatment (including nursing care, childcare, etc.) and work. Many patients require mental and financial support to help them with their work–treatment balance. In 2016, the Ministry of Health, Labor and Welfare provided guidelines for supporting employee’s work–treatment balance, and in 2018, “Consulting Fee” was approved as an insured medical treatment when clinic doctors supported their patients for continuing to work. The request for the consulting fee requires that the clinician and the occupational physician exchange information on the support necessary for the patient to continue working. Generally, occupational physicians obtain medical information from clinicians to give advice on a worker’s employment considerations. However, we do not know what kind of workplace information clinicians hope to know when treating their patients. Therefore, we conducted this survey to clarify how occupational physicians could provide useful information to clinicians. Methods: We asked approximately 1,500 occupational physicians from the Occupational Health Subcommittee of the Japan Society for Occupational Health to provide us with a letter sent to their clinician to assist workers. From the collected letters, the structural parts of the letters (titles, greetings, acknowledgments, etc.) were removed. We defined a section as a contextual unit that does not impair the meaning. The prepared sections underwent qualitative inductive analysis using the content analysis method of “Berelson, B.” Results: A total of 103 cases and 178 documents from 42 people were included in the analysis. Extracting descriptions that could be interpreted as providing information, including descriptions related to treatment, employment, and living environment, and opinions and suggestions from occupational physicians resulted in 596 sections. As a result of the qualitative and inductive classification, the information was classified into three large categories that consisted of information provision, opinions of occupational physicians, and information handling, five middle and eighteen small classifications. In addition, some good practices that were considered significant to clinicians were illustrated. Conclusions: We analyzed and categorized the information present in the letters sent by occupational physicians to clinicians. The letter does not need to contain all the information in the category table. However, it is important that it should have the necessary and sufficient information considering the case in question. We believe that this category table will aid occupational physicians in writing letters to clinicians.